[Wien] Problem creating struct files from VASP contcar files

[Florent Boucher]

Dear Patrick,
your cell effectively corresponds to a monoclinic lattice but not a 
primituve one. I was able to find the monoclinic C centered unit cell 
doing this transformation:
a' = - c
b' = 2a + c
c' = -b

Then I got the following C centered lattice :
a' = 5.1782
b' = 8.8046
c' = 5.1857
beta = 112.81

In VASP you enter the primitive triclinic unit cell and the program is 
able to find the higher symmetry. Wien works in a different way : you 
enter the non primitive unit cell and it does the job for you to reduce 
the number of k point and find the corresponding primitive cell.

However, for non primitive monoclinic unit cell, WIEN works only with 
CXZ lattice (b-base centered, monoclinic gamma). So you have to use the 
following transformation according to your primitive cell :
a' = - c
b' = -b
c' = -2a - c
I got :
Crystal system    monoclinic
Space group    B 1 1 2/m (no. 12)
Unit cell dimensions
a = 5.1782 Å
b = 5.1857 Å
c = 8.8046 Å
gamma = 112.81 °

I put in attachement a cif file.
Regards
Florent

pjr8 a écrit :

>Hello,
>
>I'm new to using wien 2k, so I hope I'm not missing a simple solution to this.
> I'm trying to convert VASP contcar files for low symmetry structures, like 
>monoclinic, into struct files.  A sample contcar file is pasted below.
>
>GSS check structure #: 81
>    4.100000000000000
>     1.0062816128952770    0.5260273706595530    0.5121801204340521
>    -0.4948479628567789    1.0535466565671180    0.4948479628567789
>    -0.4941014924612246   -1.0520547413191060    0.4941014924612247
>   6   3
>Direct
>  0.3333333333333428  0.7607588622281583  0.8969830898152509
>  0.6694622253955771  0.7390086361365178  0.5980793830199076
>  0.9972044412710943  0.7390086361365178  0.2619504909576591
>  0.6694622253955771  0.2609913638634822  0.0713828423756695
>  0.9972044412710943  0.2609913638634822  0.7352539503134352
>  0.3333333333333428  0.2392411377718417  0.4363502435180777
>  0.3333333333333428  0.0000000000000000  0.6666666666666572
>  0.6680618367231830  0.5000000000000000  0.8340309183616057
>  0.9986048299434884  0.5000000000000000  0.4993024149717371
>
>The first line (after the title) is the scale factor, the next three lines 
>define the basis vectors, and the nine atom positions are listed in direct 
>coordinates.  Using StructGen, I entered a=5.105, b=5.187, c=5.178 and 
>alpha=112.8, beta=120.5, gamma=78.6.  The atom positions were entered in 
>direct coords as above.
>
>When I run init_lapw it keeps identifying it as a triclinic structure.  I have 
>also tried placing a single atom at 0,0,0 to see if it would show up as 
>monoclinic, but it doesn't.
>
>Any help is appreciated.
>
>Thanks,
>
>Patrick Robbins
>
>_______________________________________________
>Wien mailing list
>Wien at zeus.theochem.tuwien.ac.at
>http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>
>  
>


-- 
 --------------------------------------------------------------------------
| Florent BOUCHER                    |                                     |
| Institut des Matériaux Jean Rouxel | Mailto:Florent.Boucher at cnrs-imn.fr  |
| 2, rue de la Houssinière           | Phone: (33) 2 40 37 39 24           |
| BP 32229                           | Fax:   (33) 2 40 37 39 95           |
| 44322 NANTES CEDEX 3 (FRANCE)      | http://www.cnrs-imn.fr              |
 --------------------------------------------------------------------------

-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: B112_m.CIF
Url: http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20040107/9ace70ee/B112_m.ksh